Structure and Microwave Properties of Thick-Film Composite Materials BaSrTiO3/NiFe2O4

Multiferroic composites consisting of barium–strontium titanate and nickel ferrite have been successfully synthesized by low-temperature sintering in the form of thick films on a dielectric substrate. The crystal structure and composition of the composites were studied by X-ray diffraction and electron microscopy. The electrical and magnetic characteristics of the obtained composites were studied at microwaves. The studied samples demonstrate a dielectric permittivity from 80 to 160 and dielectric losses from 0.05 to 0.1 at a frequency of 1 GHz, as well as the ability to control the magnetization of the composite within 30% by changing the magnetization field in the range 0–2000 Oe. This is the first successful attempt to synthesize a ferroelectric/ferrite composite with both low microwave losses and magnetization controllability.